Wireless device, method, and computer readable media for signaling a short training field in a high-efficiency wireless local area network

ABSTRACT

Apparatuses, methods, and computer readable media for signaling high efficiency short training field are disclosed. A high-efficiency wireless local-area network (HEW) station is disclosed. The HEW station may comprise circuitry configured to: receive a trigger frame comprising an allocation of a resource block for the HEW station, and transmit a high efficiency short training field (HE-STF) with a same bandwidth as a subsequent data portion, wherein the transmit is to be in accordance with orthogonal frequency division multiple access (OFDMA) and wherein the transmit is within the resource block. A subcarrier allocation for the HE-STF may match a subcarrier allocation for the subsequent data portion. The HE-STF and the subsequent data portion may be transmitted with a same power. A total power of active subcarriers of the HE-STF may be equal to or proportional to a second total of data subcarriers and pilot subcarriers of the subsequent data portion.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.14/751,551, filed Jun. 26, 2015, which claims the benefit of priorityunder 35 USC 119(e) to U.S. Provisional Patent Application Ser. No.62/072,272, filed Oct. 29, 2014, each of which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

Embodiments pertain to wireless communications in a wireless local-areanetwork (WLAN) such as Institute of Electrical and Electronic Engineers(IEEE) 802.11. Some embodiments relate to signaling a high efficiencyWLAN short training field (HE-STF). Some embodiments relate to using theHE-STF to determine an automatic gain control (AGC) for receivingsubsequent data using orthogonal frequency division multiple-access(OFDMA).

BACKGROUND

Efficient use of the resources of a WLAN is important to providebandwidth and acceptable response times to the users of the WLAN.However, often there are many devices trying to share the same resourcesand the devices may interfere with one another. Moreover, wirelessdevices may need to operate with both newer protocols and with legacydevice protocols.

Thus there are general needs for systems and methods for signaling highefficiency signal fields that may be used to determine an AGC forreceiving subsequent data.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements and in which:

FIG. 1 illustrates a WLAN in accordance with some embodiments;

FIG. 2 illustrates a preamble structure in accordance with someembodiments;

FIG. 3 illustrates a HE-STF in accordance with some embodiments;

FIG. 4 illustrates a HE-STF subcarrier allocation in accordance withsome embodiments;

FIG. 5 illustrates a HE-STF active subcarrier allocation in accordancewith some embodiments;

FIG. 6 illustrates a ¼ down sampled HE-STF active subcarrier allocationin accordance with some embodiments; and

FIG. 7 illustrates a HEW device in accordance with some embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 illustrates a WLAN 100 in accordance with some embodiments. TheWLAN may comprise a basis service set (BSS) 100 that may include amaster station 102, which may be an AP, a plurality of high-efficiencywireless (HEW) (e.g., IEEE 802.11ax) STAs 104 and a plurality of legacy(e.g., IEEE 802.1n/ac) devices 106.

The master station 102 may be an AP using the IEEE 802.11 to transmitand receive. The master station 102 may be a base station. The masterstation 102 may use other communications protocols as well as the IEEE802.11 protocol. The IEEE 802.11 protocol may be IEEE 802.11ax. The IEEE802.11 protocol may include using OFDMA, time division multiple access(TDMA), and/or code division multiple access (CDMA). The IEEE 802.11protocol may include a multiple access technique. For example, the IEEE802.11 protocol may include space-division multiple access (SDMA) and/orMU-MIMO.

The legacy devices 106 may operate in accordance with one or more ofIEEE 802.11 a/g/ag/n/ac, IEEE 802.11-2012, or another legacy wirelesscommunication standard. The legacy devices 106 may be STAs or IEEE STAs.

The HEW STAs 104 may be wireless transmit and receive devices such ascellular telephone, handheld wireless device, wireless glasses, wirelesswatch, wireless personal device, tablet, or another device that may betransmitting and receiving using the IEEE 802.11 protocol such as IEEE802.11ax or another wireless protocol. In some embodiments, the HEW STAs104 may be termed high efficiency (HE) stations.

The BSS 100 may operate on a primary channel and one or more secondarychannels or sub-channels. The BSS 100 may include one or more masterstations 102. In accordance with some embodiments, the master station102 may communicate with one or more of the HEW devices 104 on one ormore of the secondary channels or sub-channels or the primary channel.In accordance with some embodiments, the master station 102 communicateswith the legacy devices 106 on the primary channel. In accordance withsome embodiments, the master station 102 may be configured tocommunicate concurrently with one or more of the HEW STAs 104 on one ormore of the secondary channels and a legacy device 106 utilizing onlythe primary channel and not utilizing any of the secondary channels.

The master station 102 may communicate with legacy devices 106 inaccordance with legacy IEEE 802.11 communication techniques. In exampleembodiments, the master station 102 may also be configured tocommunicate with HEW STAs 104 in accordance with legacy IEEE 802.11communication techniques. Legacy IEEE 802.11 communication techniquesmay refer to any IEEE 802.11 communication technique prior to IEEE802.11ax.

In some embodiments, a HEW frame may be configurable to have the samebandwidth as a sub-channel, and the bandwidth may be one of 20 MHz, 40MHz, or 80 MHz, 160 MHz, 320 MHz contiguous bandwidths or an 80+80 MHz(160 MHz) non-contiguous bandwidth. In some embodiments, bandwidths of 1MHz, 1.25 MHz, 2.0 MHz, 2.5 MHz, 5 MHz and 10 MHz, or a combinationthereof or another bandwidth that is less or equal to the availablebandwidth, may also be used. A HEW frame may be configured fortransmitting a number of spatial streams, which may be in accordancewith MU-MIMO.

In other embodiments, the master station 102, HEW STA 104, and/or legacydevice 106 may also implement different technologies such as codedivision multiple access (CDMA) 2000, CDMA 2000 1×, CDMA 2000Evolution-Data Optimized (EV-DO), Interim Standard 2000 (IS-2000),Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Long TermEvolution (LTE), Global System for Mobile communications (GSM), EnhancedData rates for GSM Evolution (EDGE), GSM EDGE (GERAN), IEEE 802.16(i.e., Worldwide Interoperability for Microwave Access (WiMAX)),BlueTooth®, or other technologies.

Some embodiments relate to HEW communications. In accordance with someIEEE 802.11ax embodiments, a master station 102 may operate as a masterstation which may be arranged to contend for a wireless medium (e.g.,during a contention period) to receive exclusive control of the mediumfor an HEW control period. In some embodiments, the HEW control periodmay be termed a transmission opportunity (TXOP). The master station 102may transmit a HEW master-sync transmission, which may be a triggerframe or HEW control and schedule transmission, at the beginning of theHEW control period. The master station 102 may transmit a time durationof the TXOP and sub-channel information. During the HEW control period,HEW STAs 104 may communicate with the master station 102 in accordancewith a non-contention based multiple access technique such as OFDMA orMU-MIMO. This is unlike conventional WLAN communications in whichdevices communicate in accordance with a contention-based communicationtechnique, rather than a multiple access technique. During the HEWcontrol period, the master station 102 may communicate with HEW stations104 using one or more HEW frames. During the HEW control period, the HEWSTAs 104 may operate on a sub-channel smaller than the operating rangeof the master station 102. During the HEW control period, legacystations refrain from communicating. In accordance with someembodiments, during the master-sync transmission the HEW STAs 104 maycontend for the wireless medium with the legacy devices 106 beingexcluded from contending for the wireless medium during the master-synctransmission.

In some embodiments, the multiple-access technique used during the HEWcontrol period may be a scheduled OFDMA technique, although this is nota requirement. In some embodiments, the multiple access technique may bea time-division multiple access (TDMA) technique or a frequency divisionmultiple access (FDMA) technique. In some embodiments, the multipleaccess technique may be a space-division multiple access (SDMA)technique.

The master station 102 may also communicate with legacy stations 106and/or HEW stations 104 in accordance with legacy IEEE 802.11communication techniques. In some embodiments, the master station 102may also be configurable to communicate with HEW stations 104 outsidethe HEW control period in accordance with legacy IEEE 802.11communication techniques, although this is not a requirement.

In example embodiments, the master station 102 and/or HEW stations 104are configured to perform one or more of the functions and/or methodsdescribed herein in conjunction with FIGS. 1-7 such as transmitting andreceiving HE-SIGs and using the received HE-SIG to determine an AGC forreceiving a subsequent data field.

FIG. 2 illustrates a preamble structure 200 in accordance with someembodiments. Illustrated in FIG. 2 are a legacy short training field(L-STF) 202, a legacy long training field (L-LTF) 204, a legacy signalfield (L-SIG) 206, a very-high throughput signal A field (VHT-SIG-A)208, a VHT-SIG-B 210, a very-high throughput short training field(VHT-STF) 212, a very-high throughput long training field (VHT-LTF) 214,a second VHT-LTF 216, a second VHT-SIG-B 218, and a data field 220.

The L-STF 202 and the L-LTF 204 may be 12 orthogonal frequency divisionmultiplexing (OFDM) symbols that may include information forsynchronizing timers, selecting antennas, or other information. TheL-SIG field 206 may be used to describe the data rate and length of theframe. The VHT-SIG-A 208 field and VHT-SIG-B 210 field may be only usedby master stations 102, HEW stations 104, and legacy devices 106 thatare configured to operate in accordance with IEEE 802.11ac.

The VHT-STF 212 may be a field to help the master station 102, HEWstation 104, and/or legacy device 106 tune in the signal. The VHT-LTF214 may be a field that comprises a sequence of symbols that set updemodulation of the rest of the frame. The second VHT-LTF 216 may be aduplicate of the VHT-LTF 214 or include additional information. TheVHT-SIG-B 218 may be a duplicate of the VHT-SIG-B 210 or may containadditional information. The data field 222 may comprise higher layerpackets which may include an aggregate frame comprising multiplehigher-layer packets.

The master stations 102, HEW stations 104, and legacy devices 106 may beconfigured with AGC for OFDMA. The AGC may use the energy estimated froma short training field such as L-STF 202 or VHT-STF 212 to adjust thesignal path gain and make the AGC loop converged in order to lower theanalog to digital clipping and quantization noise.

FIG. 3 illustrates a HE-STF 304 in accordance with some embodiments.Illustrated in FIG. 3 are a station 302, a HE-STF 304, and a HE-STF ¼down sampled 306. The frequency 308, 310, 312 is illustrated along ahorizontal axis for the station 302, the HE-STF 304, and the HE-STF ¼down sampled 306, respectively. The station 302 may be a master station102 or a HEW station 104. The scheduled subchannel 320 indicates asubchannel that is scheduled for the station 302 for a downlinktransmission. The scheduled subchannel 320 may have been indicated in atrigger frame received by the scheduled station 302. The scheduledsubchannel 320 may be a portion of an 80 MHz bandwidth. For example, thesubchannel 320 may be 2.5 MHz or another bandwidth less than or equal to80 MHz.

The HEW STF 304 may be for a bandwidth of 80 MHz. The HE-STF 304 is asubcarrier allocation. The HE-STF 304 may be used for IEEE 802.11ac. Insome embodiments the HE-STF 304 is a subcarrier allocation that may beused in IEEE 802.11ax. The symbol duration in IEEE 802.11ax may be fourtimes longer than in IEEE 802.11ac. The arrows indicate subcarriers 350.Subcarriers 318 are within the scheduled subchannel 320. In someembodiments subcarriers may be termed tones. In some embodiments arrowsthat are not ghosted may be active subcarriers and arrows that areghosted are part of a subcarrier pattern but are not active. Forexample, subcarrier 515 (FIG. 5) is ghosted so it may be part of asubcarrier pattern, but may not be active.

In some embodiments beam forming may be used to send the scheduledsubchannel 320 portion of the HE-STF 304 to the station 302. Ifbeamforming is used in the downlink, then the station 302 may receivelittler power from other portions of the HE-STF 304 except thesubchannel 320 portion. The station 302 may only receive the subcarriers318 that are included in the scheduled subchannel 320 portion of thescheduled subchannel 320.

The station 302 may not be able to predict the total received power ofthe data portion (e.g., 220 of FIG. 2) because the subcarriers 318 ofthe HE-STF 304 are not dense enough in the subchannel 320 for anaccurate estimation of the power. For example, as illustrated, there areonly four subcarriers 318 in the subchannel 320. The HE-STF 304 mayinclude a portion of the scheduled subchannel 320 where there are nosubcarriers 316.

For each resource allocation such as the subchannel 320 the total powerof both the data subcarriers (e.g., the subcarriers of data 220 of FIG.2) and the pilot subcarriers should be equal to or proportionallyrepresented by the total power of the corresponding HE-STF 304 tones forthe station 320 to improve the AGC.

The HE-STF ¼ down sampled 306 may be subcarriers 314 that are a samplingdensity in frequency of every 16 subcarriers of the HE-STF 304. In someembodiments other sampling densities may be used. The subcarriers 314may have a 4× symbol duration in comparison with IEEE 802.11ac. Thesubcarriers 314 of the HE-STF ¼ down sampled 306 may mean that only onesubcarrier 314 may be within the scheduled subchannel 320. Having onlyone subcarrier 314 in the scheduled subchannel 320 may cause the AGCmeasurement for the station 302 to have an energy mismatch between theportion of the HE-STF 304 within the scheduled subchannel 320 and thedata (e.g. data 220 of FIG. 2). The HE-STF ¼ down sampled 306 mayincrease repetition in time and compensate for DC offset.

FIG. 4 illustrates a HE-STF 404 subcarrier allocation in accordance withsome embodiments. Illustrated in FIG. 4 are a station 402, and a HE-STF404. The frequency 410, 412 is illustrated along a horizontal axis forthe station 402 and HE-STF 404, respectively. The arrows indicatesubcarriers 450. The station 402 may be a master station 102 or a HEWstation 104. The scheduled subchannel 420 indicates a subchannel that isscheduled for the station 402 for a downlink transmission. The scheduledsubchannel 420 may have been indicated in a trigger frame received bythe scheduled station 402. The scheduled subchannel 420 may be a portionof an 80 MHz bandwidth. For example, the subchannel 420 may be 2.5 MHzor another bandwidth less than the 80 MHz. The scheduled subchannel 420may be a subchannel that is contended for in a trigger frame randomchannel access period.

The subcarriers 450 that are active in an allocated subchannel such asscheduled subchannel 420 may be termed the active STF subcarriers. Forexample tone 414 within scheduled subchannel 420 may be termed an activeSTF subcarrier. In some embodiments the subcarriers 450 such assubcarriers 414, 415 may be distributed so that each allocation block,unit, sub-band, and/or sub-channel with the same bandwidth has a similarnumber of subcarriers 414, 415. The subcarriers 414, 415 may be evenlydistributed across the usable subcarriers except the DC and edgesubcarriers. The subcarriers 414, 415 being evenly distributed acrossthe usable subcarriers may enable the station 402 to improve AGCmeasurement. The subcarriers 414, 415 being nearly evenly distributedacross the usable tones may enable the station 402 to improve AGCmeasurement.

In some embodiments the HE-STF 404 may have the same bandwidth as anallocated bandwidth in which data is transmitted. In some embodimentsthe station 402 may transmit a HE-STF (not illustrated) in the uplinkwith a same bandwidth as an allocated or scheduled subchannel. Forexample, station 402 may transmit a HE-STF with a bandwidth that is thesame as the bandwidth of the scheduled subchannel 420.

In some embodiments a master station 102 may transmit the HE-STF 404 tothe station 402 using beam forming and the station 402 may only receivethe scheduled subchannel 420 portion without significant attenuation.The master station 102 may then transmit a subsequent data portion onthe same scheduled subchannel 420. The master station 102 may use a samesubcarrier pattern for the HE-STF 404 within the scheduled subchannel420 as for a subsequent data portion within the subchannel 420. Themaster station 102 may transmit the HE-STF 404 using a bandwidth that isgreater than the bandwidth of the scheduled subchannel 420 and which maybe the same bandwidth as a subsequent data portion which may be to morethan one station 402 and which uses OFDMA.

In the uplink, the station 402 may transmit the subcarrier 414 only as aHE-STF 404 to the master station 102. The station 402 may then transmita subsequent data portion using OFDMA to the master station 102 usingsubcarriers 414 within the scheduled subchannel. In some embodiments asame subcarrier pattern is used for the HE-STF 404 as for the subsequentdata portion.

The signal power of the active subcarriers (e.g., 450, 414, 415) of theHE-STF 404 within the scheduled subchannel 420 may match or beproportional to the total power within the scheduled subchannel 420 forthe subsequent data portion. The master station 102 and/or the HEWstation 104 may use the subcarriers 414 to determine the AGC setting forreceiving the subsequent data portion.

Using the same subcarrier pattern for both the HE-STF 404 and thesubsequent data portion in either an uplink transmission or a downlinktransmission may have the technical effect of the receiver experiencingthe same channel attenuation which may improve the AGC setting.

FIG. 5 illustrates a HE-STF 504 active subcarrier allocation inaccordance with some embodiments. Illustrated in FIG. 5 are station 502,HE-STF 504, resource block 1 520.1, resource block 2 520.2, and resourceblock 3 520.3. The frequency 514, 516 is along a horizontal axis for thestation 502 and the HE-STF 504, respectively. The station 502 may be amaster station 102 or HEW station 104. Subcarriers 550 such assubcarrier 512 may be subcarriers that are active. The ghosted arrow at514 may be an inactive or muted subcarrier 514.

The resource blocks 520 may be resource blocks allocated to the station102 for uplink or downlink transmission. In some embodiments theresource blocks 520 may be allocated to more than one station 502.

The station 502 may be allocated the resource blocks 520 in a triggerframe for uplink or downlink transmission to a master station 102. Insome embodiments the resource blocks 520 may be one or more subchannelsthe station 102 is transmitting on in the uplink. For example, thestation 502 may have received a trigger frame for random access anddetermined to transmit within the resource blocks 520. In someembodiments the resource blocks 520 may be contiguous.

Each of the resource blocks 520 may have the same number of subcarrierssuch as 26, 56, 30, or 32, or there may be a fixed number of subcarriersfor different sized resource blocks 520. The station 502 may transmitthe HE-STF 104 in a same patter for each of the resource blocks 520. Forexample as illustrated the station 502 transmits four subcarriers 550such as subcarrier 512 for resource block 2 520.2. The station 502 mayalter the pattern to leave a subcarrier inactive or mute a subcarrier550 at an edge of the bandwidth or at the DC 506. For example, mutedsubcarrier 514.

In some embodiments the tones 550 or active subcarriers are transmittedon even subcarriers so that the HE-STF 504 may be repeated in the timedomain which may assist the receiver in estimating the DC offset. Thespacing 508, 510 between the tones 550 may be the same.

In some embodiments the HE-STF 504 tone allocation will match the toneallocation in the OFDMA allocation. In some embodiments every resourceblock 220 has at last two tones. In some embodiments the HEW device 104is configured to transmit a separate HE-STF 504 in each resource block520.

FIG. 6 illustrates a ¼ down sampled HE-STF 604 active subcarrierallocation in accordance with some embodiments. Illustrated in FIG. 6are scheduled station 602 and ¼ down sampled HE-STF 604. The frequency614, 616 is along a horizontal axis for the scheduled station 602 and ¼down sampled HE-STF 604, respectively.

The scheduled station 602 may include a resource block for scheduledstation 1 620 and a resource block for scheduled station 0 622.Subcarriers 650 such as subcarrier 606 and subcarrier 607 are activesubcarriers and are indicated with up arrows. The scheduled station 602,which as illustrated are station 1 and station 0, may be a masterstation 102 or HEW station. Resource block for station 1 620 may be aresource block of an allocation for station 1. Resource block forstation 0 622 may be a resource block for an allocation for station 0.The ¼ down sampled HE-STF 602 may be a down sampling of the HE-STFtransmission of the scheduled station 602 or may be the received signalsof the scheduled station 602 which was transmitted by a master station102 or HEW station 104.

Down sampling may change the ratio between the number of subcarriers 650in a HE-STF and the corresponding data portion of the subcarriers 650.Resource block for scheduled station 0 622 has only one subcarrier 607and may have 32 data portion subcarriers while the resource block forscheduled station 1 620 of the same size as resource block for scheduledstation 0 622 has two active tones 606. In some embodiments thescheduled station 602 are configured to adjust the power used for thesubcarrier 607 for the HE-STF when the number of active subcarriers 607varies. For example, station 0 may transmit active subcarrier 607 withtwice the power as station 0 transmits active subcarriers 606. The powercompensation may be used both in the uplink by station 0 and in adownlink transmission by a master station 102 where the subcarrier 607indicates a subcarrier received by station 0.

For uplink transmissions or for downlink transmissions the scheduledstation 102 may have a small allocated resource block such as subchannelof 2.5 MHz.

FIG. 7 illustrates a HEW device in accordance with some embodiments. HEWdevice 700 may be an HEW compliant device that may be arranged tocommunicate with one or more other HEW devices, such as HEW STAs 104(FIG. 1) or master station 102 (FIG. 1) as well as communicate withlegacy devices 106 (FIG. 1). HEW STAs 104 and legacy devices 106 mayalso be referred to as HEW devices and legacy STAs, respectively. HEWdevice 700 may be suitable for operating as master station 102 (FIG. 1)or a HEW STA 104 (FIG. 1). In accordance with embodiments, HEW device700 may include, among other things, a transmit/receive element 701 (forexample an antenna), a transceiver 702, physical (PHY) circuitry 704,and media access control (MAC) circuitry 706. PHY circuitry 704 and MACcircuitry 706 may be HEW compliant layers and may also be compliant withone or more legacy IEEE 802.11 standards. MAC circuitry 706 may bearranged to configure packets such as a physical layer convergenceprocedure (PLCP) protocol data unit (PPDUs) and arranged to transmit andreceive PPDUs, among other things. HEW device 700 may also includecircuitry 708 and memory 710 configured to perform the variousoperations described herein. The circuitry 708 may be coupled to thetransceiver 702, which may be coupled to the transmit/receive element701. While FIG. 7 depicts the circuitry 708 and the transceiver 702 asseparate components, the circuitry 708 and the transceiver 702 may beintegrated together in an electronic package or chip.

In some embodiments, the MAC circuitry 706 may be arranged to contendfor a wireless medium during a contention period to receive control ofthe medium for the HEW control period and configure an HEW PPDU. In someembodiments, the MAC circuitry 706 may be arranged to contend for thewireless medium based on channel contention settings, a transmittingpower level, and a CCA level.

The PHY circuitry 704 may be arranged to transmit the HEW PPDU. The PHYcircuitry 704 may include circuitry for modulation/demodulation,upconversion/downconversion, filtering, amplification, etc. In someembodiments, the circuitry 708 may include one or more processors. Thecircuitry 708 may be configured to perform functions based oninstructions being stored in a RAM or ROM, or based on special purposecircuitry. The circuitry 708 may be termed processing circuitry inaccordance with some embodiments. The circuitry 708 may include aprocessor such as a general purpose processor or special purposeprocessor. The circuitry 708 may implement one or more functionsassociated with transmit/receive elements 701, the transceiver 702, thePHY circuitry 704, the MAC circuitry 706, and/or the memory 710.

In some embodiments, the circuitry 708 may be configured to perform oneor more of the functions and/or methods described herein and/or inconjunction with FIGS. 1-7 such as transmitting and receiving HE-SIGsand using the received HE-SIG to determine an AGC for receiving asubsequent data field.

In some embodiments, the transmit/receive elements 701 may be two ormore antennas that may be coupled to the PHY circuitry 704 and arrangedfor sending and receiving signals including transmission of the HEWpackets. The transceiver 702 may transmit and receive data such as HEWPPDU and packets that include an indication that the HEW device 700should adapt the channel contention settings according to settingsincluded in the packet. The memory 710 may store information forconfiguring the other circuitry to perform operations for configuringand transmitting HEW packets and performing the various operations toperform one or more of the functions and/or methods described hereinand/or in conjunction with FIGS. 1-7 such as transmitting and receivingHE-SIGs and using the received HE-SIG to determine an AGC for receivinga subsequent data field.

In some embodiments, the HEW device 700 may be configured to communicateusing OFDM communication signals over a multicarrier communicationchannel. In some embodiments, HEW device 700 may be configured tocommunicate in accordance with one or more specific communicationstandards, such as the Institute of Electrical and Electronics Engineers(IEEE) standards including IEEE 802.11-2012, 802.11n-2009, 802.11ac-2013, 802.11ax, DensiFi, standards and/or proposed specifications forWLANs, or other standards as described in conjunction with FIG. 1,although the scope of the invention is not limited in this respect asthey may also be suitable to transmit and/or receive communications inaccordance with other techniques and standards. In some embodiments, theHEW device 700 may use 4× symbol duration of 802.11n or 802.11ac.

In some embodiments, an HEW device 700 may be part of a portablewireless communication device, such as a personal digital assistant(PDA), a laptop or portable computer with wireless communicationcapability, a web tablet, a wireless telephone, a smartphone, a wirelessheadset, a pager, an instant messaging device, a digital camera, anaccess point, a television, a medical device (e.g., a heart ratemonitor, a blood pressure monitor, etc.), an access point, a basestation, a transmit/receive device for a wireless standard such as802.11 or 802.16, or other device that may receive and/or transmitinformation wirelessly. In some embodiments, the mobile device mayinclude one or more of a keyboard, a display, a non-volatile memoryport, multiple antennas, a graphics processor, an application processor,speakers, and other mobile device elements. The display may be an LCDscreen including a touch screen.

The transmit/receive element 701 may comprise one or more directional oromnidirectional antennas, including, for example, dipole antennas,monopole antennas, patch antennas, loop antennas, microstrip antennas orother types of antennas suitable for transmission of RF signals. In somemultiple-input multiple-output (MIMO) embodiments, the antennas may beeffectively separated to take advantage of spatial diversity and thedifferent channel characteristics that may result.

Although the HEW device 700 is illustrated as having several separatefunctional elements, one or more of the functional elements may becombined and may be implemented by combinations of software-configuredelements, such as processing elements including digital signalprocessors (DSPs), and/or other hardware elements. For example, someelements may comprise one or more microprocessors, DSPs,field-programmable gate arrays (FPGAs), application specific integratedcircuits (ASICs), radio-frequency integrated circuits (RFICs) andcombinations of various hardware and logic circuitry for performing atleast the functions described herein. In some embodiments, thefunctional elements may refer to one or more processes operating on oneor more processing elements.

The following examples pertain to further embodiments. Example 1 is anapparatus of an apparatus of a high-efficiency wireless local-areanetwork (HEW) station. The HEW station including circuitry configuredto: receive a trigger frame comprising an allocation of a resource blockfor the HEW station; and transmit a high efficiency short training field(HE-STF) with a same bandwidth as a subsequent data portion, where theHE-STF is to be transmitted in accordance with orthogonal frequencydivision multiple access (OFDMA) and where the bandwidth is indicated inthe allocation and is less than 20 MHz.

In Example 2, the subject matter of Example 1 can optionally includewhere a subcarrier allocation for the HE-STF matches a subcarrierallocation for the subsequent data portion.

In Example 3, the subject matter of Examples 1 or 2 can optionallyinclude where the HE-STF and the subsequent data portion are transmittedwith a same power.

In Example 4, the subject matter of any of Examples 1-3 can optionallyinclude where a total power of active subcarriers of the HE-STF areequal to or proportional to a second total of data subcarriers and pilotsubcarriers of the subsequent data portion.

In Example 5, the subject matter of any of Examples 1-4 can optionallyinclude wherein the bandwidth is one from the following group: 1.25 MHz,2 MHz, 2.5 MHz, 5 MHz, and 10 MHz.

In Example 6, the subject matter of any of Examples 1-5 can optionallyinclude where a subcarrier pattern of the HE-STF is the same as asubcarrier pattern of the data portion.

In Example 7, the subject matter of any of Examples 1-6 can optionallyinclude where the HE-STF comprises at least two active subcarriers forthe resource block.

In Example 8, the subject matter of any of Examples 1-7 can optionallyinclude where the allocation comprises one or more additional resourceblocks for the HEW station.

In Example 9, the subject matter of Example 8 can optionally includewhere the resource block and the one or more additional resource blockshave a same subcarrier pattern for the HE-STF.

In Example 10, the subject matter of Example 8 can optionally includewhere the circuitry is further configured to transmit a separate HE-STFwithin each of the one or more additional resource blocks.

In Example 11, the subject matter of Example 8 can optionally includewhere the HE-STF and the allocation and the one or more additionalallocations have a same bandwidth.

In Example 12, the subject matter of any of Examples 1-11 can optionallyinclude where the HE-STF comprises one or more subcarriers, and wherethe one or more subcarriers are transmitted at a higher power tocompensate for one or more muted subcarriers, where the one or moremuted subcarriers are muted for one of the reasons from the followinggroup: an out-of-band emission, peak to average power ratio (PAPR)reduction, and DC.

In Example 13, the subject matter of any of Examples 1-12 can optionallyinclude where the HE-STF comprises a plurality of evenly spacedsubcarriers.

In Example 14, the subject matter of any of Examples 1-13 can optionallyinclude where the HE-STF comprises at least one subcarrier transmittedwith a greater power than other subcarriers to compensate for a lowernumber of subcarriers in a portion of the resource block.

In Example 15, the subject matter of any of Examples 1-14 can optionallyinclude where the circuitry is further configured to: receive a secondallocation of a second resource block, wherein the second allocation isfor a downlink transmission from a master station; and receive a secondHE-STF with a second same bandwidth as a bandwidth of a total allocationof a plurality of HEW stations, wherein the HEW station is one of theplurality of HEW stations and wherein each subchannel of the totalallocation has a same or proportional power.

In Example 16, the subject matter of Example 15 can optionally includewhere the circuitry is further configured to determine an automatic gaincontrol (AGC) from the second HE-STF, and wherein the AGC is for asubsequent data portion.

In Example 17, the subject matter of any of Examples 1-16 can optionallyinclude where a pattern of subcarriers is repeated for at least two of aplurality of sub-channels of the resource block.

In Example 18, the subject matter of Example 17 can optionally includewhere a spacing between subcarriers of the at least two of the pluralityof subchannels is a same frequency.

In Example 19, the subject matter of any of Examples 1-18 can optionallyinclude where active subcarriers of the HE-STF are one-quarter downsampled in comparison to the subsequent data portion, and where at leastone of the active subcarriers is power compensated due to a fewer numberof active subcarriers within a subchannel of the resource allocation.

In Example 20, the subject matter of any of Examples 1-19 can optionallyinclude memory coupled to the circuitry; and, one or more antennascoupled to the circuitry.

In Example 21, the subject matter of any of Examples 1-20 can optionallyinclude where the circuitry further comprises processing circuitry andtransceiver circuitry.

Example 22 is a method performed on a wireless local-area network (HEW)station. The method including receiving a trigger frame comprising anallocation of a resource block for the HEW station; and transmitting ahigh efficiency short training field (HE-STF) with a same bandwidth as asubsequent data portion, wherein the HE-STF is to be transmitted inaccordance with orthogonal frequency division multiple access (OFDMA).

In Example 23, the subject matter of Example 22 can optionally includewhere a subcarrier allocation for the HE-STF matches a subcarrierallocation for the subsequent data portion.

Example 24 is a non-transitory computer-readable storage medium thatstores instructions for execution by one or more processors on awireless communication device. The operations configure the wirelesscommunication device to: receive a trigger frame comprising anallocation of a resource block for the HEW station; and transmit a highefficiency short training field (HE-STF) with a same bandwidth as asubsequent data portion, wherein the HE-STF is to be transmitted inaccordance with orthogonal frequency division multiple access (OFDMA).

In Example 25, the subject matter of Example 24 can optionally includewhere the HE-STF and the subsequent data portion are transmitted with asame power.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. An apparatus of a high-efficiency (HE) stationcomprising: memory; and, processing circuitry coupled to the memory, theprocessing circuitry configured to: decode at least a portion of aphysical layer convergence procedure (PLCP) protocol data unit (PPDU),the PPDU comprising a field comprising a first allocation, the firstallocation comprising an indication of a first resource block for the HEstation, wherein the first resource block is one of a plurality of firstresource blocks for a plurality of HE stations for receipt of downlinkdata within a data portion of the PPDU, the PPDU further comprising afirst HE short training field (HE-STF) with a bandwidth of the pluralityof first resource blocks, wherein the HESTF is to be transmitted beforethe data portion, and wherein the PPDU carries a trigger frame, thetrigger frame comprising a second allocation, the second allocationcomprising an indication of a second resource block for the HE station,wherein the second resource block is one of a plurality of secondresource blocks for uplink PPDUs from the plurality of HE stations tothe HE access point in response to the trigger frame; and generatesignaling to cause the HE station to wirelessly transmit an UL PPDUcomprising a second HE-STF with a bandwidth of the second resourceblock, wherein the second HE-STF is to be transmitted in accordance withorthogonal frequency division multiple access (OFDMA) and wherein thebandwidth of the second resource block is less than 20 MHz.
 2. Theapparatus of claim 1, wherein the first HE-STF comprises at least twonon-zero subcarriers for the first resource block.
 3. The apparatus ofclaim 2, wherein the total bandwidth of the plurality of first resourceblocks is 20 MHz.
 4. The apparatus of claim 3, wherein the first HE-STFand the second HESTF comprise a plurality of evenly spaced subcarriers.5. The apparatus of claim 4, wherein the second resource block and eachresource block of the plurality of second resource blocks have a samebandwidth.
 6. The apparatus of claim 5, wherein the first HE-STFcomprises a plurality of subcarriers, and wherein a spacing betweennon-zero subcarriers of the plurality of subcarriers is a constantnumber of subcarriers.
 7. The apparatus of claim 6, wherein theprocessing circuitry is configured to: transmit the second HE-STF and asubsequent data portion with a same power, wherein the subsequent dataportion is to be transmitted in accordance with the second resourceblock.
 8. The apparatus of claim 7, wherein the trigger frame furthercomprises data for the HE station, and wherein the HE station is toreceive the data within the first resource block.
 9. The apparatus ofclaim 8, wherein the second HE-STF comprises subcarriers, and where theprocessing circuitry is configured to: transmit one or more subcarriersof the subcarriers at a higher power to compensate for one or more othersubcarriers that are muted, wherein the one or more other subcarriersare muted for one of the reasons from the following group: anout-of-band emission, peak to average power ratio (PAPR) reduction, andDC.
 10. The apparatus of claim 9, the first HE-STF comprises a pluralityof subcarriers and the subcarriers are evenly distributed across theplurality of first resource blocks.
 11. The apparatus of claim 10,wherein the processing circuitry is further configured to determine anautomatic gain control (AGC) from the first HE-STF, and wherein the AGCis for a subsequent data portion to be received within the firstresource allocation.
 12. The apparatus of claim 11, wherein the HEstation and the HE AP are each one from the following group: anInstitute of Electrical and Electronic Engineers (IEEE) 802.11ax accesspoint, an IEEE 802.11ax station, an IEEE 802.11 station, and an IEEE802.11 access point.
 13. The apparatus of claim 12, further comprisingtransceiver circuitry coupled to the processing circuitry; and, one ormore antennas coupled to the transceiver circuitry.
 14. A non-transitorycomputer-readable storage medium that stores instructions for executionby one or more processors of an apparatus of a high-efficiency (HE)station, the operations to configure the one or more processors to:decode at least a portion of a physical layer convergence procedure(PLCP) protocol data unit (PPDU), the PPDU comprising a field comprisinga first allocation, the first allocation comprising an indication of afirst resource block for the HE station, wherein the first resourceblock is one of a plurality of first resource blocks for a plurality ofHE stations for receipt of downlink data within a data portion of thePPDU, the PPDU further comprising a first HE short training field(HE-STF) with a bandwidth of the plurality of first resource blocks,wherein the HESTF is to be transmitted before the data portion, andwherein the PPDU carries a trigger frame, the trigger frame comprising asecond allocation, the second allocation comprising an indication of asecond resource block for the HE station, wherein the second resourceblock is one of a plurality of second resource blocks for uplink PPDUsfrom the plurality of HE stations to the HE access point in response tothe trigger frame; and generate signaling to cause the HE station towirelessly transmit an UL PPDU comprising a second HE-STF with abandwidth of the second resource block, wherein the second HE-STF is tobe transmitted in accordance with orthogonal frequency division multipleaccess (OFDMA) and wherein the bandwidth of the second resource block isless than 20 MHz.
 15. The non-transitory computer-readable storagemedium according to claim 14, wherein the first HE-STF comprises atleast two non-zero subcarriers for the first resource block.
 16. Thenon-transitory computer-readable storage medium according to claim 15,wherein the first HE-STF comprises at least two active subcarriers forthe first resource block.
 17. A method performed by an apparatus of ahigh-efficiency (HE) station, the method comprising: decoding at least aportion of a physical layer convergence procedure (PLCP) protocol dataunit (PPDU), the PPDU comprising a field comprising a first allocation,the first allocation comprising an indication of a first resource blockfor the HE station, wherein the first resource block is one of aplurality of first resource blocks for a plurality of HE stations forreceipt of downlink data within a data portion of the PPDU, the PPDUfurther comprising a first HE short training field (HE-STF) with abandwidth of the plurality of first resource blocks, wherein the HESTFis to be transmitted before the data portion, and wherein the PPDUcarries a trigger frame, the trigger frame comprising a secondallocation, the second allocation comprising an indication of a secondresource block for the HE station, wherein the second resource block isone of a plurality of second resource blocks for uplink PPDUs from theplurality of HE stations to the HE access point in response to thetrigger frame; and generating signaling to cause the HE station towirelessly transmit an UL PPDU comprising a second HE-STF with abandwidth of the second resource block, wherein the second HE-STF is tobe transmitted in accordance with orthogonal frequency division multipleaccess (OFDMA) and wherein the bandwidth of the second resource block isless than 20 MHz.
 18. The method of claim 17, wherein the first HE-STFcomprises at least two active subcarriers for the first resource block.19. An apparatus of a high-efficiency (HE) access point (AP), theapparatus comprising: memory; and, processing circuitry coupled to thememory, the processing circuitry configured to: encode a physical layerconvergence procedure (PLCP) protocol data unit (PPDU), the PPDUcomprising a plurality of first resource blocks for a downlinktransmission from the HE access point to a plurality of HE stations forreceipt of downlink data within a data portion of the PPDU, the PPDUfurther comprising a first HE short training field (HE-STF) with abandwidth of the plurality of first resource blocks, wherein the HE-STFis to be transmitted before the data portion, and wherein the PPDUcarries a trigger frame, the trigger frame comprising a secondallocation, the second allocation comprising a plurality of secondresource blocks for uplink PPDUs from the plurality of HE stations tothe HE access point in response to the trigger frame; generate signalingto cause the HE AP to wirelessly transmit the PPDU; and decode data fromthe plurality of HE stations in accordance with the plurality of secondresource block, wherein the data from the plurality of the HE stationsis preceded by second HESTFs, wherein the second HE-STFs have a samebandwidth as a corresponding second resource block, and wherein thebandwidth is less than 20 MHz.
 20. The apparatus of claim 19, whereinthe first HE-STF comprises at least two active subcarriers for the firstresource block.
 21. The apparatus of claim 19, wherein the totalbandwidth of the plurality of first resource blocks is 20 MHz.
 22. Theapparatus of claim 19, wherein the first HE-STF and the second HESTFcomprise a plurality of evenly spaced subcarriers.
 23. The apparatus ofclaim 19, wherein the first HE-STF comprises a plurality of subcarriers,and wherein a spacing of subcarriers of the plurality of subcarriers isa same number of subcarriers.
 24. The apparatus of claim 19, wherein thesecond resource block and each of the plurality of second resourceblocks have a same bandwidth.
 25. The apparatus of claim 19, furthercomprising transceiver circuitry coupled to the processing circuitry;and, one or more antennas coupled to the transceiver circuitry.